When my son was an infant we got the advice to let the fever run its course from our doc. He ended up having a febrile seizure from the temp. Scariest moment of my life. Never again, we treated his fevers after that.
https://www.google.com/health/ref/Febrile+seizures
I don't care what the docs say, I've watched a friends daughter turn into a veritable vegetable from uncontrolled seizures that started when she was 1, it wasn't something I was going to screw around with.